I was a PO(RP1) on the Interservice Hovercraft Unit which became the RNNHTU - I was a Hovercraft Navigator & also the Hovercraft Navigators Training Officer, the course was run by the Navigation section HMS Dryad and all Navigators were fish heads & not ACMN.
Two of my former colleagues were attached to the hovercraft unit as navigators , they were very definitely Royal Navy Aircrewmen !
